单项选择题
（）means navigational and meteorological warnings, meteorological forecasts and other urgent related messages broadcast to ships.
A.Navigational broadcast B.weather forecast C.Urgency message D.Maritime Safety Information
单项选择题 （）is designed to send an automatic distress alert when a ship sinks suddenly.
单项选择题 （）process the distress signal from EPIRB to determine its position and identity.
单项选择题 It is（）for mariners to combine the SART with a float-free satellite EPIRB.
